The invention relates to the equipment for conducting mass- and heat-exchange processes and deals with the construction of contact plates for gas and liquid reaction. The contact plate according to the invention may be most advantageously used in column apparatus for separation of gas and liquid mixtures by the methods of refining and absorption, for catching dust and other solids from gases with liquids. The invention will find application in the chemical, petrochemical oil refinery and other industries.
There is a widely known contact plate for column apparatus comprising a base having apertures for the passage of ascending gas flow therethrough and supporting receiving and discharge pockets for liquid. In operation of the apparatus, liquid which gets to the plate base is distributed thereover to define, upon reaction with gas, an interphase contact surface at which physico-chemical processes occur, and the liquid flows towards the discharge pocket. Such is the organization of flow in the sieve, valve, cap and other types of contact plates having discharge means.
However, in view of evergrowing volume of processed starting products and more stringent requirements imposed on quality of separated products, more attention is given in the Soviet and foreign practice to the development and employment of highly active and efficient contact plates for stable operation over a wide load range, which permit higher flow velocities in the apparatus, while retaining high separating ability.
This problem may be most successfully solved by providing, on the contact plate, a directive gas flow into the liquid or directive gas flow from the liquid. For that purpose, the admission of gas to the contact plates is effected by using oriented scales, valves, plates and apertures. In order to prolong the residence time of liquid, the apertures are frequently made in different directions. To reduce secondary mixing and eliminate stagnation zones, the contact plates are divided by means of partition walls into a number of longitudinal or transverse sections. The same sections are intended to serve as separators of liquid from gas, that is to reduce losses.
The analysis of operation of the prior art contact plates, however, shows that they have a number of disadvantages: either low velocity of gas in the apparatus, or narrow range of stable operation; either short residence time of the flows or considerable losses of liquid to the upper contact plates (the partition walls may be a source of secondary losses); either non-uniform distribution of liquid over the working surface of the contact plate or substantial secondary mixing of liquid, or insufficient development of the interphase surface. The provision of means for application and removal of heat on the plate may result in substantially impaired hydrodynamic situation at the contact plate.